1. Field of the Invention
Embodiments of the present invention relate to a hard disk drive, and more particularly, to a hard disk drive having a disk spacer supporting information storage disks and a spindle motor including the disk spacer.
2. Description of the Related Art
Hard disk drives (HDDs), which may store information for computers, read and/or write data inform/to a disk using a read/write head. In HDDs, the read/write head may operate by being moved to a desired position while flying at a predetermined height above a surface of the disk.
FIG. 1 illustrates a conventional HDD, with FIG. 2 illustrating a spindle motor, disks, a spacer, and a clamp coupled to one another in a HDD, such as the conventional HDD of FIG. 1.
Referring to FIGS. 1 and 2, a spindle motor 30 may rotate disks 21 and 22, which are data-storage recording media, and an actuator 40 may move a read/write head over any of the disks 21 and 22 for data reproduction and/or recording from a desired portion of the disks 21 and 22. As illustrated, disks 21 and 22 may further be installed on a base member 11 of the HDD.
While the two disks 21 and 22 may be mounted on the spindle motor 30, as shown in FIGS. 1 and 2, a single disk, or even additional disks may be mounted on the spindle motor 30. When the plurality of disks 21 and 22 are mounted on the spindle motor 30, a ring-shaped disk spacer 50 may be used to maintain a distance between the disks 21 and 22. The disk spacer 50 can be fitted around an outer circumference of a hub 32 of the spindle motor 30, to be interposed between the disks 21 and 22. A clamp 55 may be used to firmly fix the disks 21 and 22 to the spindle motor 30, with the clamp 55 being coupled to an upper portion of the spindle motor 30 using clamp fastening screws 56.
The actuator 40 may include a swing arm 42 rotatably coupled to a pivot shaft 41 installed on the base member 11, a suspension 43 installed at one end of the swing arm 42 and elastically biasing a slider 44, on which the read/write head may be mounted toward surfaces of the disks 21 and 22, and a voice coil motor (VCM) 45 to rotate the swing arm 42. The VCM 45 may be controlled by a servo control system, and rotate the swing arm 42 in a direction according to Fleming's Left Hand Rule, due to an interaction between current input to a VCM coil and a magnetic field formed by magnets. That is, if the HDD is turned on and the disks 21 and 22 begin to rotate, the VCM 45 may rotate the swing arm 42 in a direction to move the read/write head over recording surfaces of the disks 21 and 22. In contrast, if the HDD is turned off and the disks 21 and 22 stop rotating, the VCM 45 may rotate the swing arm 42 in an opposite direction to remove the read/write head from over the surfaces of the disks 21 and 22.
A cover member 12 may be joined to the base member 11, using a plurality of cover fastening screws 19. Here, a gasket 14 may also be interposed between the base member 11 and the cover member 12 to seal the HDD. The joined base member 11 and cover member 12 surround and protect the disks 21 and 22, the spindle motor 30, the actuator 40, etc., for example.
In this conventional HDD, the rotating disks 21 and 22 may flutter due to structural defects of the spindle motor 30, deflection of the disks 21 and 22 during an assembly process, and turbulent airflow inside the HDD. In particular, non-negligible airflow may be generated around the rapidly rotating disks 21 and 22. The airflow may cause the disks 21 and 22 to vibrate. Once such vibrations of the disks 21 and 22 occur, track mis-registration (TMR) may be caused, thereby increasing position error signals (PESs) and degrading data reproduction and recording performance of the HDD. Particularly, as the data recording densities of disks 21 and 22 have recently been rapidly rising, disk vibration problems have become even worse.
In an attempt to solve these problems, a thin plate-shaped disk damper 60 may be inserted between the disks 21 and 22. If the disk damper 60 is installed between the disks 21 and 22, there remains a narrow space between the disk damper 60 and each of the disks 21 and 22, and thus the disk damper 60 may deaden the vibrations of the disks 21 and 22 due to a damping effect of compressed air between the disks 21 and 22.
However, if an abrupt external impact is applied to the HDD having the disk damper 60 between the disks 21 and 22, the disks 21 and 22 may contact the disk damper 60, thereby damaging the data recording surfaces of the disks 21 and 22. Also, if three or more disks are implemented in the HDD, there is a little room in the HDD interior, and thus, such a disk damper is difficult to install in the HDD.